A temperature-responsive biosensing film consisting of the temperature-responsive block co-polymer poly (N-isopropylacrylamide)-b-poly(2-acrylamidoethyl benzoate) (referred to as PNIPAM-b-PAAE), graphene oxide (GO), and hemoglobin (Hb) was fabricated and used to modify a glassy carbon electrode (GCE). The film provides a favorable micro-environment for Hb to facilitate the electron transfer to the GCE. Hb at PNIPAM-b-PAAE/GO/Hb (PGH) film exhibits a couple of well-defined redox peaks with a formal potential of ?0.371 V (vs. SCE) and displays intrinsic electro-catalytic activity toward H2O2. The sensing film also shows temperature-tunable catalytic activity toward H2O2 that can be stimulated by temperature. Large peak currents can be seen in amperometry at 0.4 V (vs. SCE) in pH 7.0 phosphate buffer only if the temperature is above the lower critical solution temperature (LCST) of 32 °C. The response of the modified GCE is linear in the 0.1 to 3.7 μmol L?1 concentration range if operated at above 32 °C, but in the 0.2 to 3.7 μmol L?1 concentration range at below 30 °C. This behavior is attributed to the temperature-dependent phase transition of PNIPAM-b-PAAE and cooperative effect of GO. The strategy presented here in our perception meets the requirements of switchable sensors for use in bioscience and biotechnology.
Graphical abstract A temperature-responsive biosensing film consisting of temperature-responsive polymer, graphene oxide and hemoglobin has been fabricated. This film displays favorable electrochemical property and good electro-catalytic activity toward H2O2. It also exhibits catalytic activity change upon temperature stimuli.
We disclose herein the first example of merging photoredox catalysis and copper catalysis for radical 1,4-carbocyanations of 1,3-enynes. Alkyl N-hydroxyphthalimide esters are utilized as radical precursors, and the reported mild and redox-neutral protocol has broad substrate scope and remarkable functional group tolerance. This strategy allows for the synthesis of diverse multi-substituted allenes with high chemo- and regio-selectivities, also permitting late stage allenylation of natural products and drug molecules.An efficient synthesis of multi-substituted allenes by metallaphotoredox-catalyzed decarboxylative 1,4-carbocyanation of 1,3-enynes is described.相似文献
Structural and biochemical studies elucidate that PAN may contribute to the host protein shutdown observed during influenza A infection. Thus, inhibition of the endonuclease activity of viral RdRP is an attractive approach for novel antiviral therapy. In order to envisage structurally diverse novel compounds with better efficacy as PAN endonuclease inhibitors, a ligand-based-pharmacophore model was developed using 3D-QSAR pharmacophore generation (HypoGen algorithm) methodology in Discovery Studio. As the training set, 25 compounds were taken to generate a significant pharmacophore model. The selected pharmacophore Hypo1 was further validated by 12 compounds in the test set and was used as a query model for further screening of 1916 compounds containing 71 HIV-1 integrase inhibitors, 37 antibacterial inhibitors, 131 antiviral inhibitors and other 1677 approved drugs by the FDA. Then, six compounds (Hit01–Hit06) with estimated activity values less than 10 μM were subjected to ADMET study and toxicity assessment. Only one potential inhibitory ‘hit’ molecule (Hit01, raltegravir’s derivative) was further scrutinized by molecular docking analysis on the active site of PAN endonuclease (PDB ID: 6E6W). Hit01 was utilized for designing novel potential PAN endonuclease inhibitors through lead optimization, and then compounds were screened by pharmacophore Hypo1 and docking studies. Six raltegravir’s derivatives with significant estimated activity values and docking scores were obtained. Further, these results certainly do not confirm or indicate the seven compounds (Hit01, Hit07, Hit08, Hit09, Hit10, Hit11 and Hit12) have antiviral activity, and extensive wet-laboratory experimentation is needed to transmute these compounds into clinical drugs. 相似文献
Narrowband organic light-emitting diodes (OLEDs) are receiving significant attention and have demonstrated impressive performance in blue and green OLEDs. However, developing high-performance narrowband red OLEDs remains a highly desired yet challenging task. Herein, we have developed narrowband red fluorescent emitters by utilizing a boron-dipyrromethene (BODIPY) skeleton in combination with a methyl-shield strategy. These emitters exhibit small full-width at half-maxima (FWHM) ranging from 21 nm (0.068 eV) to 25 nm (0.081 eV) and high photoluminescence quantum yields (ΦPL) ranging from 88.5 % to 99.0 % in toluene solution. Using BODIPY-based luminescent materials as emitters, high-performance narrowband red OLEDs have been assembled with external quantum efficiency as high as 18.3 % at 623 nm and 21.1 % at 604 nm. This work represents, to our knowledge, the first successful case of achieving NTSC pure-red OLEDs with the Commission Internationale de l’Éclairage (CIE) coordinates of [0.67, 0.33] based on conventional fluorescent emitters. 相似文献
B- and N-embedded multiple resonance (MR) type thermally activated delayed fluorescence (TADF) emitters usually suffer from slow reverse intersystem crossing (RISC) process and aggregation-caused emission quenching. Here, we report the design of a sandwich structure by placing the B−N MR core between two electron-donating moieties, inducing through-space charge transfer (TSCT) states. The proper adjusting of the energy levels brings about a 10-fold higher RISC rate in comparison with the parent B−N molecule. In the meantime, a high photoluminescence quantum yield of 91 % and a good color purity were maintained. Organic light-emitting diodes based on the new MR emitter achieved a maximum external quantum efficiency of 31.7 % and small roll-offs at high brightness. High device efficiencies were also obtained for a wide range of doping concentrations of up to 20 wt % thanks to the steric shielding of the B−N core. A good operational stability with LT95 of 85.2 h has also been revealed. The dual steric and electronic effects resulting from the introduction of a TSCT state offer an effective molecular design to address the critical challenges of MR-TADF emitters. 相似文献
Developing cost-effective and sustainable acidic water oxidation catalysts requires significant advances in material design and in-depth mechanism understanding for proton exchange membrane water electrolysis. Herein, we developed a single atom regulatory strategy to construct Co−Co dinuclear active sites (DASs) catalysts that atomically dispersed zirconium doped Co9S8/Co3O4 heterostructure. The X-ray absorption fine structure elucidated the incorporation of Zr greatly facilitated the generation of Co−Co DASs layer with stretching of cobalt oxygen bond and S−Co−O heterogeneous grain boundaries interfaces, engineering attractive activity of significantly reduced overpotential of 75 mV at 10 mA cm−2, a breakthrough of 500 mA cm−2 high current density, and water splitting stability of 500 hours in acid, making it one of the best-performing acid-stable OER non-noble metal materials. The optimized catalyst with interatomic Co−Co distance (ca. 2.80 Å) followed oxo-oxo coupling mechanism that involved obvious oxygen bridges on dinuclear Co sites (1,090 cm−1), confirmed by in situ SR-FTIR, XAFS and theoretical simulations. Furthermore, a major breakthrough of 120,000 mA g−1 high mass current density using the first reported noble metal-free cobalt anode catalyst of Co−Co DASs/ZCC in PEM-WE at 2.14 V was recorded. 相似文献
